WO1995009306A1 - Damper for a hydraulic pilot valve - Google Patents

Abstract

A damper for a hydraulic pilot valve wherein a plurality of pressure reducing valves, a rotating shaft, an operating member mounted on the rotating shaft and a manipulating member for rotating the rotating shaft are provided on a valve main body and wherein the pressure reducing valves are operated by the operating member through the rotation of the rotating shaft by means of the manipulating member, characterized in that said damper device is provided in the valve main body and imparts operating resistance to the operating member by virtue of viscous resistance of a highly viscous fluid.

Description

 Description Damper device for hydraulic pilot valve

Technical field

 The present invention relates to a damper device for a hydraulic pilot valve used for construction machines and industrial machines. Background art

 As the hydraulic pilot valve, a spool is slidably inserted into the valve body, an operating member slidably supported by the valve body is opposed to the spool, and an operating member is attached to the operating member. There is a known type in which a pilot pressure oil is supplied by operating an operating member by an operating member and pushing a spool.

 A hydraulic pilot valve for a traveling circuit such as a power shovel is mounted on a lower surface of a floor panel of a cab, and is operated when an operator sitting on a seat provided on the floor panel operates the hydraulic pilot valve. A very long operating member has been installed for ease of use.

 For this reason, the operating member may move arbitrarily due to inertial force due to vibration of the vehicle body and the like, which may cause the operating member to swing and push the spool to supply pilot pressure oil, thereby causing the vehicle to travel. It is very dangerous because the fluid motor may malfunction.

 In order to solve this problem, a hydraulic pilot valve equipped with a damper device has been proposed.

For example, as shown in Japanese Utility Model Laid-Open Publication No. 4-5 A hydraulic damper device in which a mechanical damper device is attached to the vehicle body or a hydraulic damper device that restricts the movement of a spool by using hydraulic oil as shown in Japanese Utility Model Laid-Open Publication No. Known are those that are incorporated into the valve body.

 However, in the former case, the mechanical damper device is located outside the valve body, so that the installation area becomes large, and the installation work becomes very troublesome.

 In the latter case, the above-mentioned problem can be solved.However, since hydraulic oil is used, the viscosity of the hydraulic oil greatly changes depending on the temperature, and stable damper performance cannot be obtained. . That is, when the temperature is low and the viscosity of the hydraulic fluid is high, the vibration damping effect of the operating member is large, but when the temperature is high and the viscosity of the hydraulic fluid is low, the vibration damping effect of the operating member is small. Becomes

 Therefore, an object of the present invention is to provide a damper device for a hydraulic pilot valve in which the installation area of the hydraulic pilot valve does not increase and stable damper performance can be obtained. Disclosure of the invention

 In order to achieve the above object, a damper device for a hydraulic pilot valve according to the present invention includes a valve body, a plurality of pressure reducing valves, a rotating shaft, an operating member attached to the rotating shaft, and a rotating shaft. A hydraulic pilot valve, comprising: a rotating operating member, wherein the operating member rotates the rotary shaft and the operating member operates the pressure reducing valve.

It is provided in the valve main body, and provides an operating resistance to the operating member by viscous resistance of a highly viscous fluid. According to the above configuration, since the damper device for imparting the operating resistance to the operating member is mounted in the valve body, the entire hydraulic pilot valve becomes compact, and the installation area can be reduced. Since the damper device uses the viscous resistance of a highly viscous fluid with a very small change in viscosity due to temperature, the damper effect is constant even when the temperature changes, and stable damper performance can be obtained.

 Further, as a specific configuration of the damper device, a piston is rotatably inserted into a case fitted into the valve body to form an annular space between the case and the piston. Preferably, a high-viscosity fluid is sealed in an annular space to increase the rotational resistance of the piston, and the piston is connected so that the piston rotates in conjunction with the rotation shaft.

 In this configuration, a lever is attached to the piston, an arm is attached to the rotating shaft, and a pin provided on the arm is fitted into a cutout groove of the lever, whereby the piston and the rotating shaft are fitted. May be connected.

 As another specific configuration of the damper device, a piston is inserted into a case rotatably inserted into the valve body to form an annular space between the case and the piston. Preferably, a high-viscosity fluid is sealed in the annular space to increase the rotational resistance of the case, and the two are connected so that the case rotates in conjunction with the operating member.

 In this configuration, the case and the operating member may be connected by providing a protrusion on the case, forming a concave groove on the operating member, and fitting the protrusion into the concave groove.

Further, as another specific configuration of the damper device, a pair of connected pistons is fixed in the valve body, and the pair of pistons is connected to the pair of pistons. A cylinder is slidably fitted to form a cylinder chamber between the pair of pistons, and a highly viscous supporting fluid is filled in the cylinder chamber to increase the sliding resistance of the cylinder. Preferably, the two are connected so that the cylinder slides in conjunction with the rotating shaft.

 In this configuration, an arm is attached to the rotating shaft, a flange is formed on each of the pair of cylinders, and the arm is made to face between the pair of flanges. Cylinders may be connected. BRIEF DESCRIPTION OF THE FIGURES

 The invention will be better understood from the following detailed description and the accompanying drawings, which show embodiments of the invention. The embodiments shown in the accompanying drawings are not intended to specify the invention, but merely to facilitate explanation and understanding.

 In the figure,

 FIG. 1 is a front view of a hydraulic pilot valve including a first embodiment of a damper device according to the present invention.

 FIG. 2 is a cross-sectional view taken along the line II-III of FIG.

 FIG. 3 is a cross-sectional view taken along the line II-III of FIG.

 FIG. 4 is a sectional view of a hydraulic pilot valve including a second embodiment of the damper device according to the present invention.

 FIG. 5 is a sectional view taken along line VV of FIG.

 FIG. 6 is a sectional view of a hydraulic pilot valve including a third embodiment of the damper device according to the present invention.

FIG. 7 is a cross-sectional view along the line W--W in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, a damper device for a hydraulic pilot valve according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

 1 to 3 show a hydraulic pilot valve including a first embodiment of a damper device according to the present invention.

 As shown in FIG. 1 and FIG. 2, a valve body 4 is configured by mounting a plate 3 on a lower body 1 and further mounting an upper body 2 thereon. The upper main body 2 is provided with a horizontal shaft hole 5. A pair of rotating shafts 6 are rotatably supported in the shaft hole 5 via a bush 7, and each of these rotating shafts 6 has an operating member. As shown in FIG. 3, the lower main body 1 is provided with a total of four pressure-reducing valves 9 so as to face both ends of each operating member 8.

 As shown in FIG. 3, the pressure reducing valve 9 includes a spool 12 for communicating and blocking the inlet port 10 and the outlet port 11, and a retainer 13 engaged with an upper end of the spool 12. A spring 16 for urging and holding the retainer 13 at the upper end of the spool 12; and a main spring 14 for urging and holding the spool 12 through the retainer 13 to the blocking position. The upper end of the spool 1 2 is fitted with a piston 15 from above, and when the piston 15 is pushed down by the operating member 8, the spool 1 2 is turned to the communicating position. And the inlet port 10 communicates with the outlet port 11, and the pressure oil at the inlet port 10 is output to the outlet port 11.

As shown in FIG. 2, a rotary type The damper device 20 is installed.

 In this damper device 20, a case 21 having a shaft hole 21 in an upward concave portion 1a is fitted, and a pair of nylons 22 is opposed to the shaft hole 21a. So that each piston 22 does not come off with the snap ring 23 and the presser plate 24, and a small diameter portion 22a is formed in each piston 22 so that the case 21 An annular space 25 of about 0.1 to 0.15 mm is formed between the shaft hole 21a and the shaft hole 21a. A highly viscous fluid such as con oil is injected and sealed with a sealing material. A plug 27 is attached to the oil hole 26 of the piston 22. A lever 28 is fixed to a small-diameter end 2 b of the piston 22 protruding from the case 21, and a pin provided on an arm 29 bolted to the end of each of the rotating shafts 6. Reference numeral 30 is fitted in the notch groove 31 of the lever 28, and when the rotation shaft 6 rotates, the piston 22 rotates. The case 21 may be integrated with the lower body 1 and the plate 3 or may be bolted separately.

 Next, the operation of the present embodiment will be described.

 When the rotating shaft 6 is rotated by the operating member 32 attached to the end of the rotating shaft 6 such as a lever or a pedal, the operating member 8 swings and pushes down the piston 15 to connect the spool 12 to the communicating position. The pressure oil at the inlet port 10 is output to the outlet port 11.

 At this time, the piston 22 rotates together with the rotating shaft 6, and the piston 22 receives viscous resistance due to the highly viscous fluid sealed in the annular space 25. The damper function is exhibited.

Therefore, the operating member 32 is moved by the inertial force due to the vibration of the vehicle body or the like. This can be prevented by the rotational resistance of piston 22. FIGS. 4 and 5 show a hydraulic pilot valve including the second embodiment.c The difference from the first embodiment is that the piston 22 of the damper device 20 is a long and integral unit. The two ends are fixed to the plate 3 with brackets 33, and a pair of cylindrical cases 21 are rotatably fitted to the pistons 22 so that the height between them is high. An annular space 25 for enclosing the viscous fluid is formed, and a projection 34 provided integrally on the outer periphery of each case 21 is fitted into a concave groove 35 formed on the operating member 8. is there.

 In this way, when the operating member 8 swings, the case 21 rotates, and the case 21 is given rotational resistance by viscous resistance of the highly viscous fluid, so that the damper function is exhibited. You.

 The rotary damper device 20 shown in the first embodiment considers the bush 7 and the rotary shaft 6 as a case 21 and a piston 22, respectively, and the bush 7 and the rotary shaft 6 It may be constituted by forming an annular space for enclosing a highly viscous fluid between them. Of course, in such a case, the connecting structure between the damper device and the rotating shaft or the operating member is unnecessary.

 6 and 7 show a hydraulic pilot valve including the third embodiment. In the present embodiment, a linear motion damper device 40 is attached to the lower body 1.

The linear motion type damper device 40 has a pair of pistons 43 connected by a connecting rod 45 and fixed to the lower body 1 so as to be sandwiched by a pair of bolts 46. The cylinder 41 is slidably fitted to the cylinder 43 to form a cylinder chamber 44 between the pair of pistons 43. A highly viscous supporting fluid is sealed in the cylinder chamber 44 to increase the sliding resistance of the cylinder 41. Then, a pair of flanges 48 are formed in the center of the outer periphery of the cylinder 41, and the arc-shaped tip of the arm 47 attached to the rotating shaft 6 is formed at both ends 47a. The pair of flanges 48 is fitted between the pair of flanges 48 so as to contact the pair of flanges 48.

 With this configuration, when the operating member 32 is operated to rotate the rotary shaft 6, the arm 147 swings, whereby the cylinder 41 slides, and the cylinder 41 slides with respect to the cylinder 41. As a result, the sliding resistance is given by the viscous resistance of the highly viscous fluid, so that the damper function is exhibited.

 According to each of the above embodiments, since the damper device for imparting the operating resistance to the operating member 8 is mounted in the valve main body 1, the entire hydraulic pilot valve is compact, and the installation area can be reduced. Further, since the damper device utilizes the viscous resistance of a highly viscous fluid, the damper effect is constant even when the temperature changes, and stable damper performance can be obtained. Although an example has been described, it will be apparent to those skilled in the art that various modifications, omissions, and additions can be made to the disclosed embodiment without departing from the spirit and scope of the present invention. . Therefore, the present invention should not be limited to the above embodiments, but should be understood to cover the scope defined by the elements recited in the claims and their equivalents.

Claims

The scope of the claims  1. A plurality of pressure reducing valves, a rotating shaft, an operating member attached to the rotating shaft, and an operating member for rotating the rotating shaft are provided on the valve body, and the rotating shaft is rotated by the operating member. In a hydraulic pilot valve for operating the pressure reducing valve by the operating member,  A damper device for a hydraulic pilot valve, wherein the damper device is provided in the valve body, and imparts operating resistance to the operating member by viscous resistance of a highly viscous fluid.  2. A piston is rotatably inserted into a case fitted into the valve body to form an annular space between the case and the piston, and a highly viscous fluid is sealed in the annular space. The hydraulic piston according to claim 1, wherein the piston has a large rotational resistance, and the piston is connected so that the piston rotates in conjunction with the rotating shaft. Damper device for the lot valve. 3. A lever is attached to the piston, an arm is attached to the rotating shaft, and a pin provided on the arm is fitted into a cutout groove of the lever to connect the piston and the rotating shaft. 3. The damper device for a hydraulic pilot valve according to claim 2, wherein: 4. A piston is inserted into a case rotatably inserted into the valve body to form an annular space between the case and the piston, and a highly viscous fluid is sealed in the annular space. 2. The hydraulic pilot valve according to claim 1, wherein the rotation resistance of the case is increased, and the case is connected so that the case rotates in conjunction with the operating member. Dambar device. 5. A projection is provided on the case, and a concave groove is formed on the operating member. 5. The damper device for a hydraulic pilot valve according to claim 4, wherein the case and the operating member are connected by fitting the protrusion into the concave groove.  6. A pair of connected pistons is fixed in the valve body, and a cylinder is slidably inserted into the pair of pistons to form a cylinder chamber between the pair of pistons. A highly viscous supporting fluid is sealed in the cylinder chamber to increase the sliding resistance of the cylinder, and the cylinder and the cylinder are connected so that the cylinder slides in cooperation with the rotating shaft. 2. The damper device for a hydraulic pilot valve according to claim 1, wherein: 7. An arm is attached to the rotating shaft, a flange is formed on each of the pair of cylinders, and the arm is made to face between the pair of flanges. 7. The damper device for a hydraulic pilot valve according to claim 6, wherein a damper device is connected to the hydraulic pilot valve.